The data-reducing, coding/decoding of digital video signals is, in many cases, based on a motion-compensated interpolation of picture element values (interframe coding). For this purpose, movement vectors or displacement vectors are required for picture element (pixel) blocks. These movement vectors are normally generated in the encoder by means of movement estimation.
A comparison is carried out in each case for a picture element block with, for example, 8.times.8 luminance picture elements from the current image, within a search zone consisting of an enlarged picture element block of, for example, 16.times.16 luminance picture elements of the preceding image and referred to as a search window. By means of MSE (mean squared error) or MAE (mean absolute error), within the search zone, the 8.times.8 block with the highest correlation is determined and from the spatial position of the latter, compared to the block from the current image, the respective movement vector is determined.
This method is extremely computation-intensive and requires very high clock frequency rates. Even in hierarchical search methods complex and high-speed hardware is required.